Astronomers Reveal Largest 3D Map Yet of Our Local Universe

Photo: The 2MASS Redshift Survey (2MRS) has catalogued more than 43,000 galaxies within 380 million light-years from Earth. In this projection, the plane of the Milky Way runs horizontally across the center of the image. Click to enlarge. Credit: T.H. Jarrett (IPAC/SSC)

It took 10 years of painstaking calculations, but astronomers at Cambridge's Harvard-Smithsonian Center for Astrophysics have finally unveiled the most complete 3D map of our local universe yet -- an area that covers 380 million light years and an estimated 43,000 galaxies. Stargazing buffs will be delighted to hear that the survey also reveals details that were previously obscured in earlier maps. The 2MASS Redshift Survey (2MRS) is based on 2D images of galaxies generated by the earlier Two-Micron All-SkySurvey (2MASS). The 2MASS Redshift Survey survey gives preceding maps a third dimension by accounting for redshift, or light that's shifted to longer wavelengths -- or the red part of the light spectrum -- as it comes in from distant galaxies. The further away a galaxy is, the greater its redshift.

Scanning the sky in three almost-infrared wavelength bands and using two telescopes in Chile and Arizona, the researchers were able to penetrate through space dust and the so-called "Zone of Avoidance," an region of our night sky that's usually obscured by the Milky Way.

According to the press release and Wired UK, the 2MASS Redshift Survey also revealed other previously hidden celestial bodies:

The 2MRS mapped in detail areas previously hidden behind our Milky Way to better understand the impact they have on our motion. The motion of the Milky Way with respect to the rest of the universe has been a puzzle ever since astronomers were first able to measure it and found it couldn't be explained by the gravitational attraction from any visible matter. Massive local structures, like the Hydra-Centaurus region (the "Great Attractor") were previously hidden almost behind the Milky Way but are now shown in great detail by 2MRS.

Photo: The 2MASS Redshift Survey (2MRS) has catalogued more than 43,000 galaxies within 380 million light-years from Earth. In this projection, the plane of the Milky Way runs horizontally across the center of the image. Click to enlarge. Credit: T.H.